It's a divided Duck Dynasty with Willie Robertson supporting Donald Trump and patriarch Phil Robertson endorsing Ted Cruz.
Both appeared at rallies for their candidates.
The battle for celebrity endorsements is lighting up both Republican and Democratic campaigns.
Other celebrities are also on the stump.
Singer Demi Lovato joined Hillary Clinton in Iowa. Like Lena Dunham and Katy Perry, she is trying to boost Clinton’s support among college students.
Actor Kevin Spacey is comparing Trump with fictional president Frank Underwood, the ruthless politician he plays in House Of Cards.
He told CBS News: “We must remember one important distinction: one of these characters is a fictional character, and the other is a fictional character.”
Read: Trump: I Would Give Sarah Palin a Role In My Administration
Trump found himself the target of a scathing attack by conservative magazine The National Review, which called him a "political opportunist", a "huckster" and a “menace."
Trump fired back on Friday saying: “It's a dying paper. Not very many people read it any more. People don't even think about the National Review.”
The Republican Party responded by booting The National Review as co-sponsor of next month’s GOP debate in Houston.